Tray type food serving systems are known in the art, for example, the disposable tray with removable inserts disclosed in U.S. Pat. No. 3,501,044 to Stone. In the '044 patent, a light-weight frame includes a plurality of partitions dividing the frame into a plurality of individual tray portions. The tray portions are of different sizes and configurations, and include locking means for locking correspondingly sized dishes therein. However, there is no provision for insulating the food portions to maintain the temperature and to prevent transfer of heat from hot food to cold food. Additionally, the trays are designed to hold a single meal, such that each dish would hold a different portion of the meal. For example, the tray may be used to serve food on a commercial airliner. Thus, it would not be practical to use the tray of the '044 patent for serving different courses to large gatherings of people since each tray would only hold one meal, and since there is no provision for maintaining the temperature of each type of food.
In order to overcome the problem of thermal conductivity between adjacent dishes as in the tray of the '044 patent, trays with insulation between their compartments were developed. U.S. Pat. No. Re. 30,962 discloses such an insulated server tray wherein a plurality of different sized food holding receptacles or cavities are formed in the tray. The trays are designed so that one may be stacked on top of the other such that one tray serves as an enclosure for the tray immediately beneath it. Additionally, the upper tray provides peripheral insulation for the cavities of the tray immediately below. Therefore, a plurality of stacks of similarly shaped insulated food storage cavities is created. Food at essentially the same temperature is stored in cavities of the same stack such that a vertical thermal-column is created to maintain the food in each column at approximately the same temperature.
Another type of prior art insulated meal server uses both an insulated tray and an insulated cover. An example of such an insulated meal server is disclosed in U.S. Pat. No. 3,754,640 to Bridges. In the '640 patent, the server includes a tray with a plurality of different sized food holding receptacles or cavities formed therein, and a cover with a plurality of enclosed spaces which mate with the receptacles in the tray. The food holding receptacles are insulated from one another, as are the enclosed spaces, so that insulated food holding compartments are formed by the tray and cover. An insulated meal server which uses both an insulated tray and an insulated cover is also disclosed in U.S. Pat. No. 3,799,386 to Madalin et al.
The cavities of each tray portion in these insulated meal servers have a fixed size such that each tray may only be used to serve one meal to a single person. The trays are not designed such that a plurality of servings may be stored in each. Furthermore, the cavities are shaped to receive a specific size and shape of dish, bowl, cup or the like. Such insulated server trays thus cannot readily accommodate portions or food shapes beyond a standard size or shape. A person eating from the tray also cannot shift the relative position of the dishware fitted into the matingly shaped cavities.
Bulk food carriers are also known in the prior art. One type of a commercially available bulk food carrier includes a single, insulated, deep-dish server tray having a corresponding insulated cover. Each server tray is adapted to hold a standard serving pan such that the food contained in the pan is insulated from the surrounding environment. However, although each container is designed to allow bulk transport of multiple portions of a single type of food, the containers can only carry one type of food in an insulated manner. Each bulk food carrier cannot be easily adjusted so that a plurality of different sized serving portions may be transported, with the food portions insulated from each other. If it is desired to transport less than a full quantity of each type of food, there will be wasted space within each bulk food carrier. In order to transport and serve more than one type of food, a corresponding number of the carriers would have to be used to ensure that each food portion is securely transported in an insulated manner.